Going through menopause at a late age is a well-established risk factor for breast cancer. Studies show that women who go through menopause after age 55 have twice the risk of breast cancer as women who do so before age 45 [54]. This likely relates to the amount of estrogen a woman is exposed to throughout her life. A high lifetime exposure to estrogen is an important risk factor for breast cancer (for more on this, click here). The later a woman goes through menopause, the longer her breast tissue is exposed to estrogens that are released during the menstrual cycle, and the greater her lifetime exposure to estrogen.
Updated 09/12/09